From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2ACE9C43381 for ; Mon, 18 Mar 2019 14:59:28 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EFC5420850 for ; Mon, 18 Mar 2019 14:59:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ifqJhh+2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EFC5420850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Wk998kz8w78GH7L75uzAk6FB5zR9iD70FNGFwPevIZE=; b=ifqJhh+2QQs9JV 8R5aYccEi1j1mO6RlXmMDoM9/+WdPQrOGqTbHjuuItNp0LVOM/HLl4IjUQiOMxk+wUDObD+IOXZtL c35u4pjvSjS+e/KoNkWOSzGschoFsQQ+m7mDGjMl1B3a6vlk3sAsKlVyo323R69PnSjY11WMpxV7C SQkQW356tDoyMbATnreBwQyEa12ZWSp65vNK/GSpQUjZF0ybBRl15XlHmKzjy0WxWOXojhmIqfRni 94nQ7CSbTu1d06IPamTVDXM6IFlApNQMNsXE61YOieIROYz7YEGgtZRXReaIZx6RotVfLjPIQ+/d2 6THw3hpETU3++tc1tZgg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5tjU-0000jo-MK; Mon, 18 Mar 2019 14:59:20 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5tjR-0000jS-FL for linux-arm-kernel@lists.infradead.org; Mon, 18 Mar 2019 14:59:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 01F531650; Mon, 18 Mar 2019 07:59:17 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0DE063F59C; Mon, 18 Mar 2019 07:59:13 -0700 (PDT) Date: Mon, 18 Mar 2019 14:59:11 +0000 From: Sudeep Holla To: "Dmitry V. Levin" Subject: Re: [PATCH v2 4/6] powerpc: use common ptrace_syscall_enter hook to handle _TIF_SYSCALL_EMU Message-ID: <20190318145911.GC18196@e107155-lin> References: <20190318104925.16600-1-sudeep.holla@arm.com> <20190318104925.16600-5-sudeep.holla@arm.com> <20190318142618.GA27941@altlinux.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190318142618.GA27941@altlinux.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190318_075917_517860_3BC2A14B X-CRM114-Status: GOOD ( 20.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Haibo Xu , Steve Capper , Catalin Marinas , jdike@addtoit.com, x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Oleg Nesterov , Richard Weinberger , Ingo Molnar , Paul Mackerras , Andy Lutomirski , Michael Ellerman , Thomas Gleixner , Bin Lu , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Mar 18, 2019 at 05:26:18PM +0300, Dmitry V. Levin wrote: > On Mon, Mar 18, 2019 at 10:49:23AM +0000, Sudeep Holla wrote: > > Now that we have a new hook ptrace_syscall_enter that can be called from > > syscall entry code and it handles PTRACE_SYSEMU in generic code, we > > can do some cleanup using the same in do_syscall_trace_enter. > > > > Cc: Oleg Nesterov > > Cc: Paul Mackerras > > Cc: Michael Ellerman > > Signed-off-by: Sudeep Holla > > --- > > arch/powerpc/kernel/ptrace.c | 48 ++++++++++++++++-------------------- > > 1 file changed, 21 insertions(+), 27 deletions(-) > > > > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > > index 2e2183b800a8..05579a5dcb12 100644 > > --- a/arch/powerpc/kernel/ptrace.c > > +++ b/arch/powerpc/kernel/ptrace.c > > @@ -3278,35 +3278,29 @@ long do_syscall_trace_enter(struct pt_regs *regs) > > > > user_exit(); > > > > - flags = READ_ONCE(current_thread_info()->flags) & > > - (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE); > > - > > - if (flags) { > > - int rc = tracehook_report_syscall_entry(regs); > > + if (unlikely(ptrace_syscall_enter(regs))) { > > + /* > > + * A nonzero return code from tracehook_report_syscall_entry() > > + * tells us to prevent the syscall execution, but we are not > > + * going to execute it anyway. > > + * > > + * Returning -1 will skip the syscall execution. We want to > > + * avoid clobbering any registers, so we don't goto the skip > > + * label below. > > + */ > > + return -1; > > + } > > This comment is out of sync with the changed code. Still applicable indirectly as ptrace_syscall_enter just executes tracehook_report_syscall_entry, but I agree needs rewording, will update. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel